The present invention relates generally to the application of liquid acid, particularly to the application of liquid acid to a surface, and specifically, to the application of liquid acid to automobile bodies for rust repair.
In the field of automobile body repair, one of the most difficult problems encountered is how to deal with rust pitted areas, such as around door locks, around handles, under chrome trim and vinyl tops, along the lower edge of doors, rock chips that have rusted, paint blisters, etc. The reason this type of rust is so difficult to deal with is metal replacement is not warranted, but problems arise from this rust on repainting or touching up. Specifically, if all the rust particles are not completely removed, the remaining rust particles will cause the new paint to bubble within a couple of months or so. Additionally, many times heavily pitted rust areas hide little pinholes in the metal which allow moisture to slowly seep under a new paint job, causing unsightly bubbles. This is true even when the best of materials is used. Therefore, the only foolproof answer to this problem is to be absolutely sure the rust has been completely removed from the area to be refinished. However, although clearly desired, complete rust removal is very hard to accomplish. This is why many professional body shops try to limit their repair to late model automobile repair and avoid rust repair if possible. If professional body shops do take in automobiles requiring rust repair, the price reflects the difficulty of dealing with this problem, and even then, no guarantees are given for rust repair. This results in frustrated car owners who try to deal with the problem, resulting in the birth of many backyard body men.
Prior to the present invention, several methods were utilized in rust repair having various degrees of success and shortcomings. One prior method was to utilize a coarse grit grinder to remove paint and surface rust from the affected area, to utilize a body hammer to try to loosen rust and to utilize a stiff wire wheel or brush to clear the rust out of the pitted area and refinish. Drawbacks to this method were the removal of good metal through the grinding procedure resulting in weakening of the metal. Additionally, the use of a body hammer stretches the metal, causing more time to be spent in body work using fillers to straighten a panel compounding the problem if all rust is not removed, which is usually the case with this method, as the remaining rust particles will loosen and bubble the body fillers. Further, the rust pits are so small that it is virtually impossible to clean the metal thoroughly with a wire wheel or brush. Furthermore, this method does not reveal troublesome pinholes which allow seepage under the new paint job. Thus, this method generally does not result in complete rust removal and is otherwise disadvantageous including being time consuming and dirty.
Another method utilized for rust repair is to utilize products, which when sprayed over rusted areas, turns the rust to a hard black substance that is supposed to stop the rusting action and provide a solid base for a paint job. However, long term repair has not been proven and questions as to its effectiveness arise at least for very logical reasons. Specifically, even though the rust has somehow been magically changed to another more desirable substance it is still there hiding all those troublesome pinholes that will allow moisture seepage from the back side. This causes the rust action to begin again and the return of the original problem. Additionally, rust is not the best bonding agent. There is no guarantee that this magically changed rust will adhere any better in the long term. These problems will always cause some scepticism about this method of rust repair.
Sandblasting is an effective method to deal with pitted rust areas. Sandblasting does an effective job of cleaning the tiny pits and exposing the pinholes. Sandblasting, however, does have serious drawbacks as well. Although a sandblaster has been developed especially for automobile body repair which uses graphite instead of sand and which uses a vacuum which reduces but does not eliminate problems encountered with standard sandblasters, sand filters in absolutely everywhere in the automobile as well as in the shop. This results in a dirty environment requiring extensive cleaning. However, it is virtually impossible to clean all the sand from the automobile and/or the shop, and the remaining sand tends to blow out just as the final coat of the paint is being put on, ruining the desired finish. Further, due to extreme heat and pressure exerted by this method of rust repair, sandblasting warps the body panels and is usually never used on an open panel such as a door, quarter panel, hood, trunk, fender, etc., but is generally confined to wheelwell openings, door edges, and other double thick metal locations which are rigid enough to resist warpage to a greater degree. Even so, extra body work is needed to straighten any sandblasted area. Additionally, sandblasting removes good metal resulting in weakening of the metal. Further, sandblasting equipment is typically not easily accessible to most automobile shops and automobile owners and are expensive to purchase or rent. Thus, this method is similarly disadvantageous in addition to being time consuming.
Acid dipping completely removes any and all rust from any submerged metal. Typically, muratic or hydrochloric acid or phosphoric acid is used to remove rust from metal. However, this method is not widely used in automobile body repair with the exception of very expensive restoration projects for several reasons. First, a large vat of acid is required to submerge an entire automobile and related parts. Additionally, the automobile must be completely disassembled including removal of all glass, chrome, software, rubber, wiring, brake material, bearings, etc., which is a very expensive and time consuming project. Further, the automobile and related parts must be transported to an acid dipping company which is difficult due to their bulkiness and weight.
Thus, a need exists in the field of automobile body repair for removing rust which eliminates all the problems of prior methods and products. Further, a need exists for removing rust which is inexpensive, safe, absolutely clean, easy to apply and is not time consuming and completely removes any and all rust from automobile bodies.